Broccoli seeds have a high amount of glucosinolates, including glucoraphanin, glucoiberin, glucoerucin. While the glucosinolates are not biologically active, cleavage by the enzyme myrosinase (present in many plant cells and in the gut microflora) results in the formation of active isothiocyanates. These isothiocyanates, including sulforaphane, have been shown to have numerous health-promoting properties, and in some experiments have even been shown to exert various anti-cancer effects.
Previously, various authors have developed extraction/purification schemes to obtain glucoraphanin from broccoli seeds. For example, West et al. 2002 J. Chromatog A 966:227-232 describes use of ion-pair and hydrophilic interaction chromatographies for purifying various glucosinolates. See also Toribio et al. 2007 J. Chromatog A 1170:44-51 which describes purification of sinalbin and glucoraphanin using strong ion-exchange displacement centrifugal partition chromatography. However, both these techniques are directed to purification of compounds, and not merely extracting a glucoraphanin-containing extract from broccoli seeds which is economical and uses food-grade reagents.
It would be desirable to have a simple, robust glucosinolate extraction method which is suitable for production of food-grade or nutraceutical-grade glucosinolates, especially glucoraphanin.